A Coast Guard vessel flipped over early Thursday during a rescue near Rockaway Beach in Queens, New York, spilling five crew members into the frigid waters.

The crew members were wearing protective gear and swam ashore uninjured, The Associated Press reported. The subjects of the rescue operation, seven men on a fishing boat that ran aground, were rescued by helicopter. The 25-foot Coast Guard boat drifted to shore.

Waves had reached heights between 10 and 12 feet when the Coast Guard received a distress call from the fishing boat, Carolina Queen III, around 2 a.m., according to the AP. The 76-foot fishing vessel was taking on water.

"They could've had some mechanical issues," Coast Guard Lieutenant William Stewart told the local station. "There could have been a number of things that went wrong that then lead us to a series of events where we're at now."

FDNY Chief George Healy said the rough conditions may have been deceiving.